NT - TROPICAL LOWS DRIVING POTENTIAL SEVERE WEATHER OVER THE TOP END. DRIER FOR THE SOUTH

The weather over the Top End is very changeable and volatile with a pair of tropical lows wafting through the Top End producing significant weather for the island chains offshore, the Tiwi Islands and Coburg Peninsula through to Cape Wessel.


The monsoonal flow is vigorous through the Arafura Sea and the MJO is expected to run through the region over the coming 2 weeks lifting rainfall chances.


But, the mesoscale (smaller scale) weather elements make forecasting very difficult for the northern areas. Forecasts can and probably will rapidly change through the period so it is important to keep abreast of the forecast packages and also the warnings.


Further south, not much south of Tennant Creek, dry hot easterly winds continuing, they could freshen for a period as well as the flow up north also increases.


Storms could be gusty north of Tennant Creek through the outlook period with damaging winds possible but rainfall totals not out of this world just yet.


Lets take a look

FORECAST

Rainfall Next 10 Days

Rainfall is expected to be very tricky to forecast over the coming days in the north with the tropical lows moving around aimlessly with slack steering currents, making it very hard to know the full scope of the impacts over northern areas of the Top End. In the south the rainfall lighter as you get past Elliot, grading to barely a drop near Tennant and nothing south from there. The moisture may begin to increase mid next week as the flow pattern over the nation begins to shift, spreading the tropical air about WA and through interior parts. We just need some low pressure to lift that into organised areas of rainfall.

Thunderstorm Forecast Thursday

Thunderstorms will continue to impact mainly the Top End of the nation as we track through Thursday with the tropical low producing locally heavy rainfall and damaging winds potential for parts of the northern coast. The track of this system is very critical in terms of placing the rainfall shield over the region, which will impact thunderstorm distribution.

Flash Flood Risk Thursday

Flash flooding is a high risk across the north coast but that risk eases rapidly as you move inland of the coast with the bands of rainfall developing in association with the tropical low skirt the coastal regions. The track of the tropical low will determine the spread of rainfall through the region and if it moves closer to the NT then the flash flood risk may spread further inland.

Tropical Low Watch

Tropical lows currently sit northeast and northwest of the Top End with the low of most concern to the NT sitting northwest of Darwin. Some models suggest that it moves westbound, others pushing it south and southeast towards the NT. This is a volatile situation and conditions could change rapidly over coming days so stay tuned.

DATA - Refer to video for more information regarding the short and medium term daily break down and much more.


GFS 00Z - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

The surface pressure pattern remains of low confidence, very complex which means that areas under severe weather potential need to pay attention to the forecast guidance, warnings and weather radar very closely over the coming days. Some areas could see high end severe weather, so if you are living under warning or excessive rainfall and thunderstorm potential, be weather aware. The west and south central areas look mostly dry and quiet. Another trough next week over the southeast offers another round of severe weather potential with severe thunderstorm activity. That system could produce more flooding issues for some parts of the southeast as well if it is allowed to pull in the moisture from the north and northeast. Tropical weather highly volatile and this will produce severe weather up north, but the track is undetermined meaning that anywhere from Darwin through to Broome need to watch closely. If that tropical low northwest of Darwin moves west bound, then rainfall numbers and moisture will start to come up for WA into March.

GFS 00Z - Precipitable Water Values - Next 2 Weeks

Very deep moisture at near record levels along the east coast will lead to above average to near record rainfall potential rivalling last years flood events. So be weather aware in these regions along the east coast. The moisture from the northeast winds will fuel an upper trough over the inland and you can see that take place on this animation. Drier air trapped back over south central and through southern WA and into the central interior. The moisture may begin to shift around the nation depending on the tracks of tropical weather over the north.

GFS 00Z - Rainfall Accumulation - Next 10 Days

Refer to video for further information

CMC 00Z - Rainfall Accumulation - Next 10 Days

Refer to video for further information

GFS 00Z - Rainfall Accumulation - Next 2 Weeks

Refer to video for further information

A closer look in - the forecast confidence is quite poor. The tropical low over the Timor Sea is expected to move south, with models bringing it east and models turning it west and some south....it is a volatile situation.

More coming up with the rainfall and model wrap after 8pm EDT, it will be interesting reading and reflection.

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